The embodiments herein relate generally to mirrors on automobiles. The challenge in mirrors on automobiles is to maximize viewing area while minimizing distortion. There is no shortage of endeavors in this regard, including: U.S. Pat. No. 3,408,136 issued to Travis; U.S. Pat. No. 6,069,755 issued to Li; U.S. Pat. No. 3,338,655 issued to Young; Published U.S. Application 2003/0081334 filed by Skinner; U.S. Pat. No. 6,199,993 issued to Mou; U.S. Pat. No. 8,128,244 issued to Lynam; U.S. Pat. No. 8,267,535 issued to Zhao; and U.S. Pat. No. 8,736,940 issued to Rawlings.
Travis and Skinner teach a rear view mirror with flat and convex elements. The convex portion is a rectangular convex shape (that is, a bent rectangle). Young uses a circular convex shape instead of a rectangle. Lynam and Rawlings add reflective portions to this mirror arrangement.
Mou and Zhao teach the familiar arrangement of having a small convex portion within an otherwise flat mirror. The present invention teaches away from this by having the round portion extend past the mirror in a number of places.
Li teaches a convex shape comprising numerous distinctive curved surfaces having a widely varying average curvature. In that regard, Li chooses average over Gaussian curvature as a design constraint.
Embodiments of the disclosed invention use a larger convex portion, defined by a different function, and measured by a different standard of consistency. In this regard, embodiments of the present invention offer an entirely unique way of solving this classical problem.
A side view mirror for an automobile is configured to maximize viewing area and minimize image distortion. The side view mirror has a flat portion, having a flat portion major axis, a flat portion minor axis and a convex portion height. A convex portion is smoothly joined to the flat portion and having a convex portion major axis, a convex portion minor axis, a convex portion height; wherein the convex portion is configured to be defined around an origin point.
In some embodiments, every point on the convex portion has a Gaussian curvature that is greater than zero. In some embodiments, the convex portion has some points with a Gaussian curvature that is greater than zero and some points with the Gaussian curvature that is less than zero causing a saddling effect on the convex portion.
In some embodiments, the convex portion height can be greater than zero. The convex portion major axis can be greater than twice the convex portion minor axis plus the convex portion height. The flat portion minor axis can be greater than three quarters the flat portion major axis. The flat portion major axis can be greater than the convex portion minor axis.
The convex portion can be defined by an ellipsoid equation:
where a is half the convex portion minor axis; b is half the convex portion major axis and c is the convex portion height.
In some embodiments, F can be equal to zero. In some embodiments, F can be equal to the convex portion height.
The detailed description of some embodiments of the invention is made below with reference to the accompanying figures, wherein like numerals represent corresponding parts of the figures.
By way of example, and referring to
∫0xEdy eqn.1
In equation 1, E is the flat portion major axis 14 which extends along the y-axis. In some embodiments, there is flat portion 10 extends in a manner not described by equation 1 but shown in
There is also the convex portion 20 which has a convex portion major axis 22, a convex portion minor axis 24, a convex portion height 26 and an origin point 28, which is provided for reference. Convex portion 20 has its geometric underpinnings in an ellipsoid equation which can be defined by equation 2.
Here, 2*a is convex portion major axis 22, 2*b is convex portion minor axis 24 and c is convex portion height 26. In some embodiments, this may serve as an adequate model to design convex surface 20. However, in other models, as shown in
The present disclosure explains that Gaussian curvature is what ultimately maximize viewing area while minimizing distortion. Gaussian curvature of equation 2 is defined as:
The Gaussian curvature for Equation 3 is a little more elaborate:
The current invention proposes that one can maximize viewing area while minimizing distortion when a, b, and c are within certain ranges. Two more variables are needed here: the flat portion minor axis 12 is d and the flat portion major axis 14 is e. The following conditions are presented:
c>0 cond. 1
a>b+c cond. 2
d>1.5*a cond. 3
2*b>e cond. 4
There are some preferred ranges:
2.125*b<e<2.375*b range 1
1.75*a<d<2.25*a range 2
1.5*a<b<2.0*a range 3
With those conditions we can now proceed to some examples:
Here, the flat portion minor axis 12 is 3.75 inches, the flat portion major axis 14 is 4.00 inches, the convex portion major axis 22 is 4.50 inches, the convex portion minor axis 24 is 2.75 inches, and the convex portion height 26 is 0.500 inches.
In this example a=1.375 inches, b=2.25 inches and c=0.5 inches d=3.75 inches and e=4.0 inches. In this model, equation 1 is utilized to define the convex portion 20. To show how the convex portion 20 changes with respect to height even measurements are made at regular intervals in the table below as shown:
Likewise, measurements can be taken in regular intervals in the x-direction with chords as shown in
Here, the flat portion minor axis 12 is 3.75 inches, the flat portion major axis 14 is 4.00 inches, the convex portion major axis 22 is 4.50 inches, the convex portion minor axis 24 is 2.75 inches, and the convex portion height 26 is 0.500 inches.
In this example a=1.375 inches, b=2.25 inches and c=0.5 inches d=3.75 inches and e=4.0 inches. In this model, equation 2 is utilized to define the convex portion 20. Equation 1 and Equation 2 are almost identical except that Equation 2 uses a major axis offset to cause a saddling effect around the edges. This saddling accomplishes the same effect as the blocking portions between the round and flat mirrors in some of the previous endeavors in this field. However, the saddling provides improved viewing portions when used sparingly. While the saddling may not appear to the naked eye, it can be proven to exist mathematically by showing points of negative Gaussian curvature,
To show how the convex portion 20 changes with respect to height even measurements are made at regular intervals in the table below as shown:
Likewise, measurements can be taken in regular intervals in the x-direction with chords as shown in
In equation 6, E is the flat portion major axis 114 which extends along the y-axis. In some embodiments, flat portion 110 extends in a manner not described by equation 1 but shown in
There is also the convex portion 120 which has a convex portion major axis 122, a convex portion minor axis 124, a convex portion truncated height 126 and an origin point 128, which is provided for reference. Convex portion 120 has its geometric underpinnings in an ellipsoid equation which can be defined by equation 2 above. However, the equation is now subject to the condition that 0<z<0.3
Here, 2*a is convex portion major axis 122, 2*b is convex portion minor axis 124 and c is a hypothetical convex portion height 126. Hypothetical convex portion height 126 is not realized because the ellipsoid is truncated. In some embodiments, this may serve as an adequate model to design convex surface 120. However, in other models, as shown in
The current invention proposes that one can maximize viewing area while minimizing distortion when a, b, and c are within certain ranges. Two more variables are needed here: the flat portion minor axis 12 is d and the flat portion major axis 14 is e. The following conditions are presented:
c>0 cond. 1
a>b+c cond. 2
d>1.5*a cond. 3
2*b>e cond. 4
There are some preferred ranges:
2.125*b<e<2.375*b range 1
1.75*a<d<2.25*a range 2
1.5*a<b<2.0*a range 3
With those conditions we can now proceed to some examples:
Here, the flat portion minor axis 112 is 3.75 inches, the flat portion major axis 114 is 4.00 inches, the convex portion major axis 122 is 4.50 inches, the convex portion minor axis 124 is 2.75 inches, and the convex portion height 126 is 0.500 inches.
In this example a=1.375 inches, b=2.25 inches and c=0.5 inches d=3.75 inches and e=4.0 inches. In this model, equation 1 is utilized to define the convex portion 120. To show how the convex portion 20 changes with respect to height even measurements are made at regular intervals in the table below as shown:
Likewise, measurements can be taken in regular intervals in the x-direction with chords as shown in
In example 3, the convex portion height is truncated creating a second flat surface.
Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specified function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. § 112, § 6. In particular, any use of “step of” in the claims is not intended to invoke the provision of 35 U.S.C. § 112, § 6.
Persons of ordinary skill in the art may appreciate that numerous design configurations may be possible to enjoy the functional benefits of the inventive systems. Thus, given the wide variety of configurations and arrangements of embodiments of the present invention the scope of the invention is reflected by the breadth of the claims below rather than narrowed by the embodiments described above.
Number | Name | Date | Kind |
---|---|---|---|
3338655 | Young | Aug 1967 | A |
3408136 | Travis | Oct 1968 | A |
3764201 | Haile | Oct 1973 | A |
6069755 | Li | May 2000 | A |
6199993 | Mou | Mar 2001 | B1 |
8128244 | Lynam | Mar 2012 | B2 |
8267535 | Zhao | Sep 2012 | B2 |
8736940 | Rawlings | May 2014 | B2 |
20030081334 | Skinner | May 2003 | A1 |
20030169521 | Hoegh | Sep 2003 | A1 |
20040212489 | Chan | Oct 2004 | A1 |
20050180034 | Schmidt | Aug 2005 | A1 |
20110317241 | Cammenga | Dec 2011 | A1 |